Aro welding machine



1,636,104 July 1927' -'r. E. MURRAY ET AL ARC WELDING MACHINE Filed Oct. 25, 1919 5 Sheets-Sheet 1 July 19, 1927.

v 'r. E. MURRAY ET AL ARC WELDING MACHINE Filed Oct. 25, 1919 5 Sheets-Sheet 2 July 19 1927.

T. i-:. MURRAY ET AL ARC WELDING MACHINE Filed Oct. 25, 1919 5 Sheets-Sheet 3 1,636,104 July 19 1927' T. E. MURRAY ET AL ARC WELDING MACHINE Filed Oct. 25, 1919 s Sheets-Shet 4 1,6 July 1927' r. E. MURRAY ET AL 36104 ARC WELDING MACHINE 5 Shets-Sheet 5 Filed Oct. 25, 1919 Patented July 19,1927.

UNITED STATES THOMAS a. momm Am) m a. woonnow, or m roar, 1am; sun woonaow ABBIGNOB '10 SAID snows-Lame nacnnm.

Application me @ctber as, me. Serial m5. seam.

The invention is an automatic are welding machine. The operation of arcwelding is determined by three principal features, namely: 1) the striking of the arc; 5 (2) the uniform and continuous feeding of the pencil electrode toward the weld, and (3) the stopping of the are. All of these intheir proper order are automatically accomplished by the present machine.

The mode or organization is as follows:

The objects to be weldedas here shown, two plates to be united edge toedge-are placed upo'n a suitable bed, over which a carriage supporting the mechanism is caused to travel in the direction of the joint. A'

fusible electrode here the end of a wire of fusible metal taken from a freely rotating reel on the carriage-is caused to follow the joint. The welding arc is struck from the end .of the wire, which is continuously fed as consumed to the joint. The wire as it is melted enters the joint, while at the same time the metal of the plates at. the joint is rendered plastic by the arc, so that said plates and wire progressively become united,

until the entire joint is completed.

In another application for Letters Patent Serial No. 305,089, filed by Harry R. Woodrow June 18, 1919, there is set forth and broadly claimed an automatic arc welding machine embodying the principle and many features of the machine herein disclosed;

Thesubject-matterjof the said application is,

' therefore, not herein claimed. The-specific construction of the machine illustrated in the said earlier application is such as to adapt it to the welding of a joint between the abutting ends of two rotating cylinders, in which case the mechanism is stationa while the work moves. In contrast to thls, the specific'construction of our present machine is such as to adapt'it tothe welding of stationary plates, or the like, over which the mechanism travels, so that instead of the joint moving in front of the arc pencil, the pencil is carried along the joint.

In the accompanying drawings Fig. 1 is an elevation of our electric arc welding machine, parts of the carriage and rod 15 being shown in section. Fig. 2 is a front elevation, a portion of the carriage, the work and the bed being here shown in section. Fig. 3 is a horizontal section on the line III, III of Fig. 2. Fig.4 is an electrical. diagram, showing the circuits and parts of the machine when not in 0 retion, Fi s. 5,6, 7 and 8 are electrica 'diagrams, s owing the circuits established and position of parts during successive stages of the operation of the-machine.

Similar letters and numbers of reference indicate like arts.

The work, ere two plates A, A of metal "to be welded. edge to edge, rests upon a bed or table. The machine is supported on the carriage'B, on opposite sides of which are brackets 5. 5 and 6, 6, Figs. 2, 3. The

carriage supporting trucks 7, 7 are journaled in brackets 5, 5. The carriage supporti'n trucks 8, 8 are carried by a shaft 9 whic extends across the carriage (Fig. 3) and is journaled in the brackets 6, 6. The trucks travel upon the work. Supported in brackets 10 on cross girders 11 of the carriage are the guide rolls 12, 13 havin beveled edges which enter the groove 14, ig. 2, formed by the correspondingly beveled'edges of the work at the joint. The guide rolls being at the front and rear of the machine and engaging the seam] at the front and rear of the welding point provide a lon line so as to hold the machine easi y and accurately to the desired direction.

Mounted on the carriageB are standards C in which is journaled the transverse rod 15 which carries the freely rotatable reel D upon which is wound any desired length 0 welding wire E. The reel is referably made removable from the stander s for purposes of refilling.

Supported upon a cross girder 16 of carguiding riage B is an electric motor F. On one end of the motor shaft is a worm 17 which engages with a pinion 18 on transverse shaft 19. A chain belt transmits power from pinion 18 to pinion 20 on shaft 9. The carriage supporting trucks 8 8 are thus driven to cause the carriage to travel over the work.

resistances.

'ng arm 26, so that said roll may against the wire E to t' htly cause said wire to be tightly gras between the feed rolls24 and 25, an drawn from the reel D. The means for p roll 24 against the wire and roll 25 is not'a part of our present invention and any suitable device may be used siic for examgle, as a clamping screw, indicated at 27, ig. 1, passing through arm 26 and engaging a lug 28 on arm G. The feedin of wire E is caused by the imtation off 'roll 25, on the shaft of which is a pinion 29 with which es a worm 30 on the end of the shaft 0 motor F opp osite to that on which worm'17 is carried.

he motor F, therefore, performs the two functions of moving the carriage B, and hence the end of the weldin wire E along the joint, and of feeding sai welding wire to said 'oint.

In or er to 'permitof the movement of arm G on its pivot shaft 21,..we inter-pose in the motor shaft two universal joints 31 and an expansion 'oint 32, whereby said motor shaft is rende flexible. V

The electrical connections. Referring to the diagram Fig. 4, J is a spring switch normally open, but closed when, b reason of the movement of carriage B on w ich it is su rted, it makes contact with a projection wwhich is .here a permanent magnet in horse-shoe form, adherent to the work and manually a plied thereto'at a particular moment, as iereinafter 'exlained. L is a manuall controlled switch. is a switch connected y a'link to arm G, which closes circuit when the right hand end of said arm is drawn down by electro-magnet H. I N is the main suppl switch communicating with the source of current (not shown) by leads d, f. O P, Q are variable The motor F is of the differential compound wound type, the shunt field b receivln its sugpily across the potential from supp switc throu h the variable a resistance The series fiel c is connected in reverse to the shunt field b, as indicated by the arrows.

The operation is as follows, the live circuits being in Fi 5, 6, 7 and 8 indicated heavy lines: e switch L is manually in closed. The circuits established arethen as in Fig. 5. The entering su pl current from main lead d passes through t lower coil e of switch N, energizing said coil, which closes said switch N, and so to closed switch L and main lead f. Switch N being closed, the current divides as follows: part proceeds through a portion of variable resistance P, to electro-magnet H, to feed roll 25, to wire E, to the brushes of motor F, to series field a, through all of variable resistance Q, and thence back to switch N and main lead f.

motor F, 'series field 0, switch- M, a

2!, 25 until its end makes contact with the and for an instant on a short circuitwill be formed throu h the work and bed, to switch N and lea Because of this ort circuiting of res1stance Q, field c and the motor, a comparatively heavy current will at once pass. to electro-mugnet H, which will .draw down the right hand end of arm G, as indicated by thedotted lines in Fig. 6. The period of time in which this short circuitin and tilting of the arm G takes place is i itesimal, so that the motor does not stop, but continues rotating by inertia. As the arm G tilts, it moves the end of the wire E away from the work,and the welding arc is at once struck between said end and the work, as indicated at 'g in Fig. 7.

The tilting of arm G also closes'switch M. The resulti circuits, as shown in Fig. 7, are then as fol ows: from main lead (1, to switch N, through a portion of variable resistance-P, electro-magnet H, feed roll 25, portion of variable resistance Q, and so to switch N and main lead f. I

As the currents in the shunt field and series field of the motor are now in opposite directions, the motor will operate at a s ed work, as shown in Fig. 6. At this instant -correspondin' to the power diflerentia of the fields, an becomes very sensitive. That is, the sli htest change in the struck arc voltage wil afiect its speed, which in turn will govern the speed of the wire feeding rolls, and also that of travel of the carriage, and hence .of movement of the wire E along the joint. Previous to the welding operation, the-motor circuit energy consumption through the variable resistances O, P, Q is exactly adjustedto 've the proper amount of current to melt e welding wire E and once set will always maintain the balance for a certain kind of ,work and welding wire. Consequently after the arc has been struck and the wire feeding and work drivin mechanism started, as described, uniform ceding of the welding wire and continuous progress of the weld are accomplished.

Returnin once more to Fig. 7 after the arc is struc and after the weld as begun, the operator applies to the work a small, preferably horse-shoe -shaped permanent magnet K, so that by its own attraction its polar ends will adhere to said work. The

Ill

position of this magnet is to be such that after the work has completed its travel and the weld is finished,'the switch J will meet the magnet and be closed thereby, as shown in Fig. 8. Circuit is thus closed through the upper coil h of switch N, whereby said switch is opened and the whole machine stopped. The completed work is then removed, and the carriage returned to its original position.

We claim:

1. An arc welding machine, comprising a portable carriage, trucks beneath said carriage and supporting the same upon the surface above which said carriage travels therefor, and, disposed on said carriage, a metal wire electrode, means for continuously feeding said wire to the weldin joint, and means for simultaneously riving said trucks and said feeding means.

2. An arc welding machine, comprising a portable carriage, a driving electric motor on and for said carriage, a metal wire electrode, means actuated by said motor for feeding said electrode to the welding joint, a movable supportfor said feeding means, and means automatically operatin to move said last-named support to carry t e end of the wire away from the work to strike the welding arc; the said motor, electrode, feeding means, feed operating means, movable support and are triking means being carried upon said carriage.

3. An arc weldin machine, as in claim 2, the said automaticafiy operating means comprising an electromagnet, and circuit connections, as set forth; whereby upon the establishment of contact of the end of the fusible electrode with the work, said magnet is energized to move said movable support and electrode to cause said electrode to strike the weldin arc.

4. An arc wel in machine comprising a portable carriage a apted to bear upon the work, means for supporting a metal wire electrode thereon, means for continuously feeding said wire to the welding joint, means simultaneously driving said carriage and said feeding means, and means for positive- 1yl guiding the carriage in the direction of t e welding joint.

' 5. An arc welding machine, as in claim 1, further including means for positively guiding the carriage in the direction of the welding joint; the said means consisting of a roller supported below said carriage and adapted to enter the gap between the objects to be welded in advance of the said electrode.

6. An arc welding machine, comprising a carriage, supporting trucks therefor, and, on said carriage, a metal wire electrode, means for continuously feeding said electrode' to the work, a movable support for said feeding means, and a driving electric motor on and for said carriage, the shaft of said motor being geared at opposite ends to said feedingmeans and said trucks.

7. An arc welding machine, comprising a carriage, a support thereon movable toward and from the work, feed rolls on said sup port, a metal wire electrode engaged by said rolls, a driving electric motor on and for said carriage, a flexible shaft transmitting power from said motor to said feed rolls, and automatically operating means for o eratin said sup rt to cause said electro e to stri e the wel ing arc.

8. An arc welding machine, com risin a fusible, electrode cooperating with t e we ding joint to strike an are at said joint, means for progressively moving said electrode along said 'oint, and means controlled b voltage variations in said are for contro ling the speed of progression of said electrode.

9. An arc welding machine, comprising a fusible electrode cooperating with the welding joint to strike an are at said joint, mechanism for feeding said electrode, means for progressively moving said electrode along said joint, and means controlled by voltage variations in said are for controlling both the speed of said feed and the speed of progression of said electrode.

In testimony whereof we have aflixed our 95 signatures.

THOMAS E. MURRAY.

HARRY R. WOODROW. 

